1. Field of the Invention
The present invention relates to a display interface method and apparatus for displaying plural objects on a computer display screen and performing an operation such as duplicating or moving the object. More specifically, the present invention relates to a method and an apparatus of displaying contents of a clipboard that provides a temporary memory when a text or an image is processed on a computer display screen.
2. Description of the Prior Art
There are two methods for duplicating or moving a text or an image that is displayed on the computer display screen to another location or program when using a program for processing the text or the image. One is called drag and drop, and another is a method using a clipboard.
In the drag and drop method, an operator uses a pointing device such as a mouse for selecting an original object, dragging the object and dropping the object at a target position. For example, the original object is held by a click operation of the mouse, which is moved to the target position for dropping. In this method, the original object as well as the target position should exist in the movable area of the mouse. Otherwise, the operation requires means for displaying the target position on the screen while holing the original object by the mouse.
In the other method using a clipboard, the original object is temporarily stored in the clipboard (that is a temporary memory). After moving to the target position on the screen, the object memorized in the clipboard is pasted at the target position.
Therefore, the method using the clipboard does not have the above-mentioned limitation in the drag and drop method and can duplicate or can move an object easily even if both the original object and the target position are displayed on the screen. In addition, this method does not need means and operations for displaying the target position on the screen while holing the original object by the mouse.
However, the method using a clipboard has a disadvantage as explained below. The substance of the clipboard is usually invisible and is pasted at the target position while the operator can remember the contents of the clipboard. Therefore, if the operator forgets the contents of the clipboard, it is not sure what will be pasted at the target position until the contents of the clipboard is actually pasted. Otherwise, additional means are required for displaying the contents of the clipboard on the screen.
This disadvantage of the method using a clipboard for duplicating or moving can be a problem particularly in a screen display using a zoom interface, which is disclosed in xe2x80x9cInformation browsing using a zoom interface,xe2x80x9d Kamiwada and Fujita, Information Processing Society of Japan, collected papers (4) of the 58th national convention, pp. 279-280, 1999, for example. It is also explained in Fujitu Journal No. 243(vol. 25, No. 3/1999).
The zoom interface is a kind of display interface developed for an application, e.g., of using a television set and its remote controller in a living room for enjoying information services provided via the Internet. The zoom interface utilizes a three-dimensional display for displaying an object in a three-dimensional manner on a screen and a zooming operation by using e.g., a remote controller. For example, the operator can access relevant information smoothly by zooming in on a portion that the operator wants to see. The operator can return to the original screen easily by zooming out. This zoom interface can be also adopted as a display interface of a current personal computer, in which a pointing device such as a mouse is used.
Using the above-mentioned zoom interface, an object can be moved or duplicated between folders in a hierarchical directory structure. In such operations, an operator may pay attention to the operation of zooming in or out and may forget the contents of the clipboard as explained above. It is indicated that until the operator becomes familiar to the operation of the zoom interface, the duplicating or the moving operation of an object between folders is difficult compared with the normal multi-window interface.
The object of the present invention is to provide a method and an apparatus for duplicating or moving an object easily using a clipboard in a zoom interface in which a display changes continuously by a zooming operation.
According to a first aspect of the present invention, a display interface method is provided for displaying plural objects on a computer display screen and performing an operation such as duplicating or moving the object. The method comprises the steps of memorizing a pointer that points an object selected by an input device in a memory, displaying a small image representing the object pointed by the pointer as a display of the foreground layer on the screen, and maintaining the display of the small image representing the object without changing even if a display of other layer is zoomed.
While the screen display is changed by the operation of zooming in or out in the zoom interface as explained above, the small image representing the selected object is stayed on the foreground layer without changing. Therefore, the operator is not required to remember the contents of the clipboard, so can concentrate on the zooming operation. In this specification, the small image means the image that is small compared with the entire screen. For example, if the object is an image file, the small image can be its thumbnail image. If the object is a text file, the small image can be an icon representing the file.
Preferably, the display interface method further comprises the steps of generating a copy of the object pointed by the pointer in accordance with an operation by the input device before a zooming operation, and pasting the copy at the position designated by the input device after the zooming operation. Thus, the selected object can be moved or duplicated to another position. If a moving operation of the object is instructed by the input device, the original object is erased when a copy of the object is generated (or is transferred to the clipboard). If a duplicating operation of the object is instructed, the original object remains without being erased.
It is also preferable that the display interface method further comprises the steps of generating link information for linking to the object pointed by the pointer in accordance with an operation by the input device before a zooming operation, and pasting the link information at the position designated by the input device after the zooming operation. In this case, what is pasted as the object (e.g., a shortcut icon) is not the copy of the original object but link information to the original object.
In any case mentioned above, it is not always a single object that is selected, but plural objects can be selected. In addition, if the clipboard stores plural objects, a part of the objects can be selected for being pasted at the target position. In this case, the display of the small image representing the pasted object can be turned off or can be stayed on for a continuous duplication to another position. Namely, there are two cases, in one of which the contents of the clipboard change, and in the other case the contents of the clipboard do not change.
It is also preferable that the display interface method further comprises the step of switching the display of the small image representing the object pointed by the pointer between on and off in accordance with an operation by the input device.
According to the second aspect of the present invention, a display interface method is provided for displaying plural objects on a computer display screen and performing an operation such as duplicating or moving the object. The method comprises the steps of generating a copy of an object selected by an input device, so as to memorize the copy in a memory, displaying a small image representing the copy memorized in the memory as a display of the foreground layer on the screen, and maintaining the display of the small image representing the copy without changing even if a display of other layer is zoomed.
In contrast to the above-mentioned first aspect in which the pointer that points the selected object is memorized, the copy of the object itself is generated and is memorized in this second aspect. In this case too, in the same way as the first aspect, the small image representing the selected image is stayed on the foreground layer without changing while the screen display is changed by the operation of zooming in or out in the zoom interface. Therefore, the operator is not required to remember the contents of the clipboard, so can concentrate on the zooming operation.
Preferably, the display interface method further comprises the step of pasting the copy memorized in the memory at the position designated by the input device after the zooming operation. Thus, the selected object can be moved or duplicated to another position.
In this second aspect too, it is preferable that the display interface method further comprises the step of switching the display of the small image representing the copy memorized in the memory between on and off in accordance with an operation by the input device.
According to the third aspect of the present invention, a display interface method is provided for displaying plural objects on a computer display screen and performing an operation such as duplicating or moving the object. The method comprises the steps of generating a copy of an object selected by an input device, so as to memorize the copy in a memory, memorizing a pointer that points the selected object in a memory, displaying a small image representing the copy memorized in the memory as a display of the foreground layer on the screen, and maintaining the display of the small image representing the copy without changing even if a display of other layer is zoomed.
The present invention also provides a display interface apparatus for performing the above-mentioned display interface method.
Furthermore, the present invention also provides a computer readable recording medium that stores a program for performing the above-mentioned display interface method.